Historically blood oxygenator technology either for short-term by-pass surgery or recently developed long-term strategies has been mass transfer limited by liquid side mass transfer fluid dynamics. Recent active mixing designs have led to systems which remove liquid side fluid limitations and have oxygen and carbon dioxide transport limited by membrane transport. Compact Membrane Systems (CMS) has identified a new family of microporous hollow fiber membranes with superior mass transfer and wet out resistance compared to commercial microporous polypropylene hollow fiber. If these new membranes are demonstrated to have superior mass transfer and wet out resistance they will further reduce the size of active mixing blood oxygenators. In Phase I, we will fabricate these microporous hollow fibers and demonstrate their superiority to commercial microporous polypropylene hollow fibers in mass transfer of blood gases (e.g. Oxygen and/or carbon dioxide) and wet out resistance. Parallel work at University of Pittsburgh will demonstrate bio-compatibility, wet-out resistance, and superior mass transfer. CMS has key industrial relations in place that if Phase I and II are successful that commercialization can be accelerated. NIH05.14? Project Narrative Active mixing membrane systems have recently been developed to support long-term blood oxygenation protocols. In these active mixing membrane systems, the overall system performance is limited by the mass transfer of the membrane itself. This program will introduce a new family of membranes with superior mass transfer compared to existing commercial microporous polypropylene hollow fibers and therefore better active mixing performance. The new family of membranes is also expected to have superior blood wet out resistance. Compact Membrane Systems, Inc. [unreadable] [unreadable] [unreadable]